Electric field heavy metal leaching device and method

Abstract

The invention relates to an electric field heavy metal leaching device and method. The electric field heavy metal leaching device comprises an upper electrode and a lower electrode which are respectively used as an anode plate and a cathode plate of the leaching electric field, wherein the two plates constitute an electric field cavity for dehydration; and the anode is a hollow plate electrode, the cathode is a metal mesh electrode, and the anode and cathode are arranged in an insulated mode and respectively connected with a positive pole and a negative pole of a direct current power supply. The method comprises the following steps: sludge with the water content of 40% or above is pressurized and injected into the electric field cavity for elution and dehydration, and moves from the inlet to the outlet in the electric field at uniform speed; meanwhile, the electric field power supply is turned on, and an acid solution is pressurized and injected via a liquid injection hole of the anode, so that harmful substances of heavy metals in the sludge are eluted under the acid production and oxidizing actions of the electric field and the combined actions of the injected acid solution; and thus, insoluble heavy metals are sufficiently dissolved in the solution and separated out along with the dehydration solution from the cathode side under the action of the electric field, and the purified sludge is discharged via the outlet. The device and method implement simultaneous actions of elution and dehydration on heavy metals. The device and method can simultaneously remove multiple heavy metals, and have wide applicability.

Description

technical field [0001] The invention belongs to a sludge acid leaching and heavy metal separation device, in particular to an electric field leaching device and method. Background technique [0002] Sludge is a by-product of sewage treatment plants. Municipal sludge is rich in nutrients such as nitrogen, phosphorus, and organic matter. More and more attention has been paid to the land use of sludge. However, heavy metals are one of the main reasons for limiting its subsequent use. Heavy metals in sludge mainly include Pb, Cd, Hg, Cr, Ni, Cu, Zn, As, etc., which have the characteristics of concealment, long-term, irreversible, etc., and are easy to be enriched through the food chain. Plants and animals cause great harm. [0003] At present, the treatment methods of heavy metals are mainly divided into two categories: stabilization and removal. Stabilization technology is to reduce the activity and availability of heavy metals by changing the existing forms of heavy metals. ...

AI Technical Summary

Problems solved by technology

Phytoremediation uses the absorption, volatilization, root filtration, degradation, and stabilization of plants to purify and transfer heavy metals. It has the advantages of being green and environmentally friendly, and has become a research hotspot in recent years. However, the plant growth cycle is long and the restoration is slow. Usually a plant Can only absorb one or two heavy metals, and plants have certain requirements on the soil

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